Your contractor will calculate the size of your roof based on measurements taken at your consultation, and use these numbers to estimate the square footage of coverage they’ll need for materials. This can be affected by how many times the direction of your roof changes. Every time your roof comes to an intersection with another section of the roof, you’ll need additional materials to ensure watertight seals.
The pitch of your roof means finding out how steep your roof is, the steeper the roof pitch, the more dangerous the job. This is a significant reason to hire a professional. Each year, thousands of people end up in emergency rooms due to falls from their roof.
Looking at the danger side of the estimate, the height of your roof plays into this cost. The higher your roof is, the farther they fall. If you’re re-roofing a single-story home, your estimate may be less than if you’re re-roofing a 3 story home.